As disclosed in Sterling Drug's U.S. Pat. No. 3,753,993 (Lesher et al.), 3,907,808 (Lesher and Carabateas), and 4,118,557 (Lesher), it is known that antibacterial 1-alkyl-1,4-dihydro-4-oxo-7-pyridinyl-3-quinolinecarboxylic acids can be prepared from 4-(3-aminophenyl)pyridine. It is also known that this route to the bactericides, as disclosed, is less economical than might be desired.
From Mitscher et al., "Quinoline Antimicrobial Agents. 1. Versatile New Synthesis of 1-Alkyl-1,3-dihydro-4-oxo-3-quinolinecarboxylic Acids," Journal of Medicinal Chemistry, 1978, Vol. 21, No. 5, pp. 485-489, it is also known that antimicrobial agents related to the aforementioned bactericides can be prepared from the appropriate isatoic anhydrides.
It would be desirable to be able to prepare the antibacterial agents of Lesher, Lesher et al, and Lesher and Carabateas by a route similar to that employed by Mitscher et al; and 4-(4-alkyl-3-nitrophenyl)pyridines, as well as 2-nitro- and 2-amino-4-(4-pyridinyl)benzoic acids and 4-(4-pyridinyl)isatoic anhydrides, that are useful in this regard are disclosed in (1) copending application Ser. No. 511,887, filed July 8, 1983, in the name of Thomas J. Walter (Walter), (2) copending application Ser. No. 511,854, filed July 8, 1983, in the name of V. Ramachandran (Ramachandran), (3) copending application Ser. No. 511,844, filed July 8, 1983, in the name of Paul F. Ranken and Thomas J. Walter (Ranken and Walter), and (4) copending application Ser. No. 523,462, filed Aug. 15, 1983, in the names of Thomas J. Walter and Paul F. Ranken (Walter and Ranken).
From Hardtmann et al., Journal of Heterocyclic Chemistry, Vol. 12, p. 565 (1975), it is known that isatoic anhydride can be alkylated with a sodium hydride/ethyl bromide system to provide a 61% yield of N-ethyl isatoic anhydride after recrystallization.